Most Labeled Penicillin-Allergic Are No Longer Intolerant

Most people whose medical record says they are allergic to penicillin are not actually allergic or intolerant. The seas been recently reported at the American College of Physicians (ACP) Internal Medicine Meeting 2021. It had also been recently published by our staff that reflected less than 2% of patients with penicillin allergy in their records are actually allergic. 

The mislabeling has implications for patient outcomes and efforts to fight antibiotic resistance.

About 10% of the general population reports a history of penicillin allergy (up to 15% of hospitalized patients), but as we have reported - up to 90% of patients with that label are able to tolerate penicillin (Penicillin skin testing in hospitalized patients with β-lactam allergies: Effect on antibiotic selection and cost). The mislabeling comes either because reactions were improperly characterized early on or people have outgrown the allergy. It appears that 

specific penicillin IgE-mediated allergy actually wanes over time - decreases such that after approximately 10 years of avoidance of a penicillin based antibiotic known as “beta-lactams”, greater than 80% of patients have a resolution of their penicillin IgE mediated allergy. Data also show patients outgrow their “oral based” aminopenicillin reactions (including those from amoxicillin and Ampicillin) faster than parenteral-based (intravenous) penicillin reactions. Patients commonly report that their parents instructed them that when they were children that they were allergic to penicillin and that information just keeps getting entered into their medical records.

Most physicians are aware the penicillin-allergic label is not always accurate, but there is hesitancy to challenge those labels because of the potential side effects and the harm that we could cause if we unlabel the patient. Also, the threat to antibiotic resistance is real, she said, when penicillin is eliminated as an option unnecessarily.

When a person is labelled allergic to penicillin, the treatment choices often go to broad-spectrum antibiotics that are more costly, have potentially worse side effects, and may contribute to resistance.

Getting tested for your real status by an allergy specialist  would help us “delabel” patients to provide the best treatment regimen which may commonly involve a penicillin based antibiotic.